The title page of this book lists Bohm as a professor emeritus at the University of London but this is actually a text developed at Princeton in the late 1940's. Not long after the book was written, Bohm had got himself in trouble for not revealing what left-wing activities he had got himself involved in with his mentor J.R. Oppenheimer. Princeton couldn't stand the political heat of having a suspected communist on its physics faculty and Bohm got booted out. He wandered off to Brazil and Israel before finally ending up in London. Ironically, Princeton had fired someone who had just written one of the greatest classics of the quantum mechanics literature. The book is outstanding for its extensive discussion of the philosophical foundations of quantum theory. Bohm at that time believed in the Copenhagen Interpretation of Niels Bohr. Only traditional mathematics, rather than the murky abstraction of the Dirac bracket, is used. Carefully selected problems are inserted into the text whenever important new material has been introduced. Although the book is a little dated, today's reader should still find the chapters on the WKB approximation, Heisenberg matrix mechanics, and perturbation theory edifying. In short, this is a book to be enjoyed.